public class ReadScrollView extends ScrollView{

    private int mScrollY = 0;

    private boolean mClampedY = false;

    public ReadScrollView(Context context) {

        super(context);

    }

    public ReadScrollView(Context context, AttributeSet attrs) {

        super(context, attrs);

    }

    public ReadScrollView(Context context, AttributeSet attrs, int defStyleAttr) {

        super(context, attrs, defStyleAttr);

    }

    /**

     * 监听变化---一般用不到

     * @param scrollX

     * @param scrollY

     * @param clampedX

     * @param clampedY

     */

//    @Override

//    protected void onScrollChanged(int l, int t, int oldl, int oldt) {

//        super.onScrollChanged(l, t, oldl, oldt);

//        if (scrollChangedListener != null){

//            scrollChangedListener.onScrollChanged(l,t,oldl,oldt);

//        }

////        DebugUtil.d("l==" + l +"  t==" + t +"  oldl==" + oldl + "  oldt=="+oldt);

//    }

    @Override

    protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {

        super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);

        //scrollY=位置0和最底y坐标;clampedY=是否到顶部或者底部

        mScrollY = scrollY;

        mClampedY = clampedY;

//        DebugUtil.d("======l==onOverScrolled"+"   scrollY="+scrollY+"  clampedY="+clampedY );

    }

    /**

     * 刷新到顶部和底部

     */

    @Override

    public void stopNestedScroll() {

        super.stopNestedScroll();

        if (mClampedY){
　　　　　　　　mClampedY = false;

            if (mScrollY == 0){

                scrollChangedListener.onScrollChangedTop();

            }else {

                scrollChangedListener.onScrollChangedBottom();

            }

        }

        DebugUtil.d("======l==stopNestedScroll" );

    }

    OnScrollChangedListener scrollChangedListener;

    public void setScrollChangedListener(OnScrollChangedListener scrollChangedListener) {

        this.scrollChangedListener = scrollChangedListener;

    }

    /**

     *

     */

    public interface OnScrollChangedListener{

        //到达顶部

        void onScrollChangedTop();

        //到达底部

        void onScrollChangedBottom();

        //监听变化

//        void onScrollChanged(int l,int t,int oldl,int oldt);

    }

}

scrollview.setScrollChangedListener(new ReadScrollView.OnScrollChangedListener() {

            @Override

            public void onScrollChangedTop() {

                ShowUtils.toast("顶部");

            }

            @Override

            public void onScrollChangedBottom() {

                ShowUtils.toast("底部");

            }

        });